base (version 3.5.1)

gettext: Translate Text Messages

Description

If Native Language Support was enabled in this build of R, attempt to translate character vectors or set where the translations are to be found.

Usage

gettext(…, domain = NULL)
ngettext(n, msg1, msg2, domain = NULL)
bindtextdomain(domain, dirname = NULL)

Arguments

…

One or more character vectors.

domain

The ‘domain’ for the translation.

n

a non-negative integer.

msg1

the message to be used in English for n = 1.

msg2

the message to be used in English for n = 0, 2, 3, ….

dirname

The directory in which to find translated message catalogs for the domain.

Value

For gettext, a character vector, one element per string in …. If translation is not enabled or no domain is found or no translation is found in that domain, the original strings are returned.

For ngettext, a character string.

For bindtextdomain, a character string giving the current base directory, or NULL if setting it failed.

Details

If domain is NULL or "", and gettext or ngettext is called from a function in the namespace of package pkg the domain is set to "R-pkg". Otherwise there is no default domain.

If a suitable domain is found, each character string is offered for translation, and replaced by its translation into the current language if one is found. The value (logical) NA suppresses any translation.

Conventionally the domain for R warning/error messages in package pkg is "R-pkg", and that for C-level messages is "pkg".

For gettext, leading and trailing whitespace is ignored when looking for the translation.

ngettext is used where the message needs to vary by a single integer. Translating such messages is subject to very specific rules for different languages: see the GNU Gettext Manual. The string will often contain a single instance of %d to be used in sprintf. If English is used, msg1 is returned if n == 1 and msg2 in all other cases.

bindtextdomain is a wrapper for the C function of the same name: your system may have a man page for it. With a non-NULL dirname it specifies where to look for message catalogues: with domain = NULL it returns the current location.

See Also

stop and warning make use of gettext to translate messages.

xgettext for extracting translatable strings from R source files.

Examples

# NOT RUN {
bindtextdomain("R")  # non-null if and only if NLS is enabled

for(n in 0:3)
    print(sprintf(ngettext(n, "%d variable has missing values",
                              "%d variables have missing values"),
                  n))

# }
# NOT RUN {
## for translation, those strings should appear in R-pkg.pot as
msgid        "%d variable has missing values"
msgid_plural "%d variables have missing values"
msgstr[0] ""
msgstr[1] ""
# }
# NOT RUN {
miss <- c("one", "or", "another")
cat(ngettext(length(miss), "variable", "variables"),
    paste(sQuote(miss), collapse = ", "),
    ngettext(length(miss), "contains", "contain"), "missing values\n")

## better for translators would be to use
cat(sprintf(ngettext(length(miss),
                     "variable %s contains missing values\n",
                     "variables %s contain missing values\n"),
            paste(sQuote(miss), collapse = ", ")))
# }